A. Field of the Invention
The present invention relates to a method and system of manufacturing lighting fixtures, in particular, a method and system of installing highly reflective inserts into a reflector frame.
B. Problems in the Art
Some wide area lighting fixtures consist of a bowl-shaped spun aluminum reflector. The bowl-shape functions as both the fixture housing and the reflecting surface. Other fixtures utilize a framework or housing into which a separate reflecting surface is placed or added. An example of this latter type is Musco Corporation U.S. Pat. No. 6,036,338 (incorporated by reference herein). A similar general bowl-shape as with conventional spun aluminum reflectors is utilized, but a cast reflector frame is used over which a plurality of wedge shaped, highly reflective strips are mounted. As discussed in U.S. Pat. No. 6,036,338, use of high reflectivity material for the strips can produce more light to the target by reducing light loss that is experienced with a spun aluminum reflector surface. Additionally, it allows flexibility in creating beam shape and characteristics. Shape, angle of curvature, and reflecting characteristics of the inserts can, for example, vary the beam width, shape, or characteristics. All the inserts can be the same or certain ones can vary. Further discussion of alternatives can be found in U.S. Pat. No. 6,036,338.
It is desirable to have relatively easy but secure mounting system for the inserts. These fixtures tend to have desired life spans of decades and can experience jostling and vibration. On the other hand, it is desirable to make assembly of such fixtures, and the mounting of a number of individual inserts per fixture, as efficient and accurate as possible.
One way to mount such thin wedge shaped inserts is shown at co-owned, co-pending U.S. Ser. No. 11/333,477 (incorporated by reference herein). A set of posts (one near the center of the reflector frame and one near its periphery) exists for each reflective insert, which has slots corresponding with the set of posts. As described in U.S. Ser. No. 11/333,477, the geometry of the posts and the slots allows the insert to basically be snapped into place on the posts. This allows for relatively easy and quick installation of inserts all the way around the reflective frame, as well as a relatively secure and durable mounting of the inserts for the intended environment of such fixtures. The design allows for either inserts of all the same type of be installed around the reflector frame or inserts of varying types in the same reflective frame to create the same or different beam shapes and characteristics, as desired. Thus, one (or just a few) standard reflector frame types can be used to create almost an unlimited number of beam shapes and characteristics by design and selection of the particular inserts assembled into for that fixture.
There can be virtually any number of reflective inserts. In the example U.S. Ser. No. 11/333,477, there are over 30 inserts per reflector frame. If manually inserted, even with the snap-in mount of the posts, this can take significant amounts of labor and time per fixture. Furthermore, especially if the design of a fixture requires a combination of different inserts, the worker must find and correctly install the correct inserts in the correct positions. The issue of accuracy of installation and assembly arises. An error in installation of even one reflector insert can materially affect the beam produced by the fixture.
Also, an important aspect for many of these types of fixtures is that they are used in sets to light an area, for example, a baseball field. In such cases, minimization of number of fixtures is a goal, because it can reduce capital costs as well as operating costs. If an error in assembling reflective inserts occurs in one fixture, it could cause not only that fixture to be erroneous, it might cause the whole lighting system to fail to meet lighting specifications for the field or target. At a minimum, it would result in lighting that is not what the customer ordered.
Therefore, there is a real need for an assembly method and system that promotes absolute accuracy in assembling such reflective inserts into a reflector frame. There is also a real need for such an assembly method and system that promotes efficiency in producing each assembled fixture. Another need is a system and method which promotes high repeatability with minimal training or skill of the assembly workers.
Presently, the burden is substantially on the worker to be right in installing the correct inserts on each fixture according to design. And, there is a substantial burden on the manufacturer to deliver the right product to the customer and meet what was specified. Once these fixtures are up on poles, it is costly and difficult to change them.